Preparation Of Graphene Oxide Composites And Their Application In Dye Adsorption

Graphene oxidation has the characteristics of quick absorption rates and large adsorption capacity due to its large specific surface area and the rich oxygen containing functional groups in the field of dye adsorption.However,the problem still exists in the process of adsorption because the graphene oxide?GO?dispersed in water easily and so it is difficult to separate.In this paper,GO has been combination with bagasse,melamine sponge and polyvinyl alcohol?PVA?respectively,and the composite materials with good adsorption performance for methylene blue?MB?was made.The results are showed as follows:Firstly,GO was loaded on the surface of the bagasse to made a compound adsorption material.The effect of the loaded quantity of GO on the adsorption was explored by static adsorption and dynamic adsorption.The results showed that the maximum adsorbing capacity of GO/Bagasse compound material for MB was 161mg/g.The main reasons of influencing adsorption performance were pH of the solution,adsorbent amount of the column filling,and quantity of the GO loaded on surface of the bagasse in the process of column adsorption.Secondly,commercial melamine sponge has been coarsened by three methods respectively,and then the sponge was modified via GO loading.The results showed that the melamine sponge was roughened by dopamine exhibited faster adsorption rate and greater adsorption capacity for MB.Finally,Two kinds of PVA/GO composite sponge were prepared via two kinds of foaming agents?sodium dodecyl sulfate and starch?.The kinetics and thermodynamics curve has been made and the adsorption performance were tested by column adsorption.The results showed that the adsorption way conforms to the Langmuir model and pseudo-second-order model.Maximum capacity of two kinds of sponge were 289.6 mg/g and 182.6 mg/g,respectively.In the process of the adsorption column,without any energy,just rely the gravity of the solution can realize the separation of the methylene blue from the water,and the water flux was 20Lm^-1h^-1.